Method and apparatus for packing an inflatable air bag in a housing of an air bag module assembly

Abstract

The present invention comprises a new and improved method and apparatus for packing an inflatable air bag cushion into a housing of an air bag module assembly of an occupant restraint system for a motor vehicle. After securing an inlet chute of the air bag cushion in the open end of the housing and placing the air bag on a flat support with a larger portion of the back wall thereof overlaying a small portion of the back wall with the front wall in between in a folded condition, a central portion of the air bag is clamped by a large blade and subsequently a first edge portion is folded over the central portion and a second opposite edge portion is folded over the first edge portion so that opposite edge fold lines extend outwardly just inside opposite ends of the housing. A rolling clamp is attached transversely across the folded air bag and the air bag is rolled-up on an axis moved toward the housing. An inverted channel element is placed over the rolled-up air bag from above and moves the air bag to a position at the open end of the housing. An outer wall of the channel element which in any upwardly retracted position causes the rolled-up bag to be inserted into the housing and a trailing end portion of the air bag is tucked into place in the housing with a tuck blade after the outer wall of the channel element is withdrawn upwardly.

What is claimed and desired to be secured by Letters Patent of the United States is: 
     
       1. A method of packing an inflatable air bag restraint cushion into a housing of an air bag module assembly for a motor vehicle occupant restraint system comprising the steps of: providing an air bag cushion comprising joined together front panel and back panel, said back panel including an inlet chute positioned between a smaller back panel portion and a larger back panel portion;   securing said inlet chute of said air bag cushion into an open end of said housing positioned between opposite end walls of said housing with said back panel and said front panel of said air bag cushion extending outwardly of said open end;   folding said larger portion of said back panel in overlaying position over said smaller portion of said back panel on a substantially flat supporting surface with said front panel folded between said back panel portions;   folding a first outer side edge portion of said air bag transversely to overlay a central portion of said back panel and folding a second opposite outer side edge portion of said air bag transversely to overlay a central portion of said back panel as well as said folded first outer side edge portion, thereby forming fold lines along opposite outer side edges of said air bag projecting outwardly of said open end and positioned inside said opposite end walls of said housing;   rolling up said air bag after folding about a roll axis toward said open end of said housing; and   moving said air bag after folding and rolling into said open end of said housing.   
     
     
       2. The method of claim 1, wherein: said central portion of said air bag is clamped against said supporting surface while said opposite outer side edge portions are being folded.   
     
     
       3. The method of claim 2, wherein: said fold lines along said opposite outer side edge portions of said air bag define a tongue having a width between said fold lines less than the distance between opposite end walls of the housing.   
     
     
       4. The method of claim 3, wherein: said tongue has a length normal to said width projecting outwardly of the open end of the housing toward an outer end of said tongue.   
     
     
       5. The method of claim 4, wherein: said rolling up of said air bag is started at a variable position along the length of the tongue spaced between the housing and the outer end of the tongue.   
     
     
       6. The method of claim 5, wherein: said rolling up of said air bag is discontinued between the position where started and the open end of the housing forming the tongue of the air bag into a partially rolled-up condition.   
     
     
       7. The method of claim 6 wherein: the air bag in partially rolled-up condition is moved to a position closely adjacent to the open end of the housing without further rolling action leaving a trailing end portion extending outwardly thereof.   
     
     
       8. The method of claim 7, wherein: said moving step initially forces said partially rolled-up air bag completely into the open end of the housing except for a portion of said trailing end portion remaining outside.   
     
     
       9. The method of claim 8 including the step of: folding of said trailing end portion remaining outside toward said air bag inside said housing.   
     
     
       10. The method of claim 9, wherein: said moving step includes a final movement of said folded up remaining trailing end portion into the open end of the housing.   
     
     
       11. A method of packing an inflatable air bag restraint cushion into a housing of an air bag module assembly for a motor vehicle occupant restraint system comprising the steps of: providing an air bag cushion comprising joined together front panel and back panel, said back panel including an inlet chute positioned between a smaller back panel portion and a larger back panel portion;   securing said inlet chute of said air bag cushion into an open end of said housing positioned between spaced opposite right and left end walls of said housing with said back panel and said front panel of said air bag cushion extending outwardly of said open end;   folding flatly said larger portion of said back panel in overlaying position over said smaller portion of said back panel with said front panel folded between said back panel portions;   folding an outer right side edge portion of said air bag transversely to the left to overlay a central portion of said back panel, forming a first fold line along the right side of said air bag projecting outwardly of said open end and positioned just inside said right end wall of said housing and leaving a leading unfolded left end portion positioned outside said left end wall of said housing;   folding said leading unfolded left end portion of said folded outer right side edge portion of said air bag transversely to the right to overlay itself, forming a second fold line along the left side of said air bag projecting outwardly of said open end and positioned just inside said left end wall of said housing;   folding an opposite outer left side edge portion of said air bag transversely to the right to overlay a central portion of said back panel and said twice folded outer right side edge portion, forming a third fold line outside of said second fold line projecting outwardly of said open end and positioned just inside the left end wall of said housing and leaving a leading unfolded right end portion positioned outside said right end wall of said housing;   folding said leading unfolded right end portion of said folded opposite outer left side edge portion of said air bag transversely to the left to overlay itself, forming a fourth fold line generally above said first fold line projecting outwardly of said open end and positioned just inside the right end wall of said housing;   rolling up said air bag after folding about a roll axis toward said open end of said housing; and   inserting said air bag after folding and rolling into said open end of said housing.